Meat enhancers might kill dangerous bacteria

University of Illinois Professor Susan Brewer stands inside her food science lab. Brewer and colleagues are researching the effect of some meat enhancers in preventing E. coli outbreaks.

You might not know it, but that juicy steak or pork chop you sometimes drool over might have been injected with a solution of salt, water and proprietary flavor enhancers.

To replace some of the taste that disappeared with the fat lost as a result of our modern, health-conscious demand for leaner meat, the meat industry took a page from the book of its poultry peers, who've been using such injections since the self-basting turkey was a new enough innovation to tout in advertising pitches.

The enhancement solution, which also can contain agents to extend shelf life, is injected by needles in processing. In some situations, runoff from the injection process is collected in a basin and recycled back through the system.

But the operation might do more than make meat taste better and last longer. It also has the potential to spread pathogens that make people sick, like virulent forms of the E. coli bacterium.

Now, University of Illinois research-ers are showing that some flavor-enhancing, shelf-life-extending solu- tions, used both alone and in concert, not only make for better-tasting meat, but actually can kill off such pathogens.

UI food science and human nutrition Professor Susan Brewer and colleagues laced meat with a benign form of E. coli and then tested the effects of sodium lactate and sodium diacetate, two natural materials used as flavor enhancers and shelf-life extenders, particularly in Britain.

Sodium lactate, a salt from lactic acid, helps give foods a tart, salty taste. Sodium diacetate, also a salt, is an active component in vinegar.

"You can't use very much of it because of the kinds of things it will do to the flavor," Brewer said recently of the latter. "Fortunately, you don't have to use very much of it."

In fact, the UI researchers used amounts too small to negatively affect taste in either case.

Brewer said both salts suppressed the growth and lowered the numbers of the bacteria in contaminated meat samples even "at high concentrations."

"You're putting way more bacteria on there than you will ever see in a natural environment," she said, adding that either of the materials alone would likely neutralize a pathogen under real-world conditions.

Moreover, sodium lactate and sodium diacetate used together left the researchers with meat samples on which they could detect no living bacteria after the treatment, despite the artificially high laboratory concentrations of the organism.

That's important in the case of pathogens like dangerous strains of E. coli, as little as 10 cells of which can make people sick.

Brewer, whose research specialty is meat processing and quality, including the microbiological aspects, emphasized that the U.S. meat supply is generally the world's most inspected and safest.

But pathogen outbreaks do occur and are big news when they happen, in part because of their rarity, Brewer said. Meat companies, already under close government scrutiny, want to avoid that kind of publicity wherever possible, which makes them open to new techniques with potential to further reduce the risk.

"The industry is aggressive about that," Brewer said. "It's in their best interest."

The UI researchers, who published their results in the Journal of Food Science and Meat Science, also examined the ways in which the processing system might promote the spread of pathogens.

The biggest threat appears to be from the injection needles pushing bacteria on the surface of meat into the interior.

If you cook meat hot enough and long enough, pathogens on or near the surface almost assuredly will be done in, as will those in the interior if you prefer your meat fully cooked.

But a lot of us enjoy a steak, for instance, that's a tad pink, if not outright bloody, on the inside. Bacteria pushed into the interior by the needles might not be heated enough to cook them to death in that case.

That's where injecting the meat with sodium lactate and sodium diacetate to enhance flavor and extend shelf life also might help reduce the risk of contamination.

The researchers looked at the possibility of the needles passing bacteria among pieces of meat moving along a processing line, and at if recycling the solution runoff is a problem. They didn't find evidence of those things.

Brewer said they expected the recycled solution to collect and build up greater numbers of bacteria as it was reused. But it proved to be, in a way, self cleaning, perhaps because its salinity dehydrates and kills the organisms, at least under lab conditions.